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class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-3 collapsed ng-star-inserted" style="position:relative" href="tutorial/toh-pt6" title="第六部分：通过 HTTP 来获取并保存英雄数据。" target="_self"><span>6. 从服务器获取数据</span></a></div></aio-nav-item></div></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><button type="button" class="vertical-menu-item heading level-2 expanded selected ng-star-inserted" title="通过数据绑定构建动态视图" aria-pressed="true"><span>组件与模板</span><mat-icon role="img" svgicon="keyboard_arrow_right" class="mat-icon notranslate rotating-icon mat-icon-no-color" aria-hidden="true"><svg focusable="false" viewBox="0 0 24 24" xmlns="http://www.w3.org/2000/svg"><path d="M8.59 16.34l4.58-4.59-4.58-4.59L10 5.75l6 6-6 6z"></path></svg></mat-icon></button><div class="heading-children level-2 expanded selected"><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-3 collapsed 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target="_self"><span>生命周期钩子</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-3 collapsed ng-star-inserted" style="position:relative" href="guide/component-interaction" title="在不同的指令和组件之间共享信息" target="_self"><span>组件交互</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-3 collapsed ng-star-inserted" style="position:relative" href="guide/component-styles" title="添加专属于某个组件的样式" target="_self"><span>组件样式</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-3 collapsed ng-star-inserted" style="position:relative" href="guide/dynamic-component-loader" title="动态加载组件" target="_self"><span>动态组件</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-3 expanded selected ng-star-inserted" style="position:relative" href="guide/elements" title="把组件转换成自定义元素" target="_self"><span>Angular 元素</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-3 collapsed ng-star-inserted" style="position:relative" href="guide/attribute-directives" title="属性型指令把行为添加到现有元素上。" target="_self"><span>属性型指令</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-3 collapsed ng-star-inserted" style="position:relative" href="guide/structural-directives" title="结构型指令可以操纵页面的布局" target="_self"><span>结构型指令</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-3 collapsed ng-star-inserted" style="position:relative" href="guide/pipes" title="管道可以在模板中转换显示的内容。" target="_self"><span>管道</span></a></div></aio-nav-item></div></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><button type="button" class="vertical-menu-item heading level-2 collapsed ng-star-inserted" title="Angular 的表单" aria-pressed="false"><span>表单</span><mat-icon role="img" svgicon="keyboard_arrow_right" class="mat-icon notranslate rotating-icon mat-icon-no-color" aria-hidden="true"><svg focusable="false" viewBox="0 0 24 24" xmlns="http://www.w3.org/2000/svg"><path d="M8.59 16.34l4.58-4.59-4.58-4.59L10 5.75l6 6-6 6z"></path></svg></mat-icon></button><div class="heading-children level-2 collapsed"><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-3 collapsed ng-star-inserted" style="position:relative" href="guide/forms-overview" title="表单可以创建集中、高效、引人注目的输入体验。Angular 表单可以协调一组数据绑定控件，跟踪变更，验证输入，并表达错误信息。" target="_self"><span>简介</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-3 collapsed ng-star-inserted" style="position:relative" href="guide/reactive-forms" title="使用 FormBuilder、表单组和表单数组创建响应式表单。" target="_self"><span>响应式表单</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-3 collapsed ng-star-inserted" style="position:relative" href="guide/forms" title="使用指令和 Angular 模板语法创建模板驱动表单。" target="_self"><span>模板驱动表单</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-3 collapsed ng-star-inserted" style="position:relative" href="guide/form-validation" title="验证用户的表单输入" target="_self"><span>表单验证</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-3 collapsed ng-star-inserted" style="position:relative" href="guide/dynamic-form" title="使用 FormGroup 渲染动态表单。" target="_self"><span>动态表单</span></a></div></aio-nav-item></div></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><button type="button" class="vertical-menu-item heading level-2 collapsed ng-star-inserted" title="Observable 与 RxJS" aria-pressed="false"><span>Observable 与 RxJS</span><mat-icon role="img" svgicon="keyboard_arrow_right" class="mat-icon notranslate rotating-icon mat-icon-no-color" aria-hidden="true"><svg focusable="false" viewBox="0 0 24 24" xmlns="http://www.w3.org/2000/svg"><path d="M8.59 16.34l4.58-4.59-4.58-4.59L10 5.75l6 6-6 6z"></path></svg></mat-icon></button><div class="heading-children level-2 collapsed"><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-3 collapsed ng-star-inserted" style="position:relative" href="guide/observables" title="" target="_self"><span>可观察对象(Observable)</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-3 collapsed ng-star-inserted" style="position:relative" href="guide/rx-library" title="" target="_self"><span>RxJS 库</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-3 collapsed ng-star-inserted" style="position:relative" href="guide/observables-in-angular" title="" target="_self"><span>Angular 中的可观察对象</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-3 collapsed ng-star-inserted" style="position:relative" href="guide/practical-observable-usage" title="" target="_self"><span>用法实战</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-3 collapsed ng-star-inserted" style="position:relative" href="guide/comparing-observables" title="" target="_self"><span>与其它技术的比较</span></a></div></aio-nav-item></div></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><button type="button" class="vertical-menu-item heading level-2 collapsed ng-star-inserted" title="Angular 中的模块" aria-pressed="false"><span>NgModules</span><mat-icon role="img" svgicon="keyboard_arrow_right" class="mat-icon notranslate rotating-icon mat-icon-no-color" aria-hidden="true"><svg focusable="false" viewBox="0 0 24 24" xmlns="http://www.w3.org/2000/svg"><path d="M8.59 16.34l4.58-4.59-4.58-4.59L10 5.75l6 6-6 6z"></path></svg></mat-icon></button><div class="heading-children level-2 collapsed"><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-3 collapsed ng-star-inserted" style="position:relative" href="guide/ngmodules" title="使用 NgModule 让你的应用更高效" target="_self"><span>NgModule 简介</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-3 collapsed ng-star-inserted" style="position:relative" href="guide/ngmodule-vs-jsmodule" title="JavaScript 模块和 NgModule 之间的差异" target="_self"><span>JS 模块 vs NgModule</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-3 collapsed ng-star-inserted" style="position:relative" href="guide/bootstrapping" title="告诉 Angular 如何在根 &quot;AppModule&quot; 中构造和引导应用。" target="_self"><span>应用的根模块</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-3 collapsed ng-star-inserted" style="position:relative" href="guide/frequent-ngmodules" title="介绍最常用的 NgModule" target="_self"><span>常用模块</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-3 collapsed ng-star-inserted" style="position:relative" href="guide/module-types" title="介绍特性模块的几种类型" target="_self"><span>特性模块的分类</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-3 collapsed ng-star-inserted" style="position:relative" href="guide/entry-components" title="关于 Angular 中入口组件的一切" target="_self"><span>入口组件</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-3 collapsed ng-star-inserted" style="position:relative" href="guide/feature-modules" title="创建特性模块，以组织你的代码" target="_self"><span>特性模块</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-3 collapsed ng-star-inserted" style="position:relative" href="guide/providers" title="服务提供商与 NgModule" target="_self"><span>服务提供商</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-3 collapsed ng-star-inserted" style="position:relative" href="guide/singleton-services" title="创建单例服务" target="_self"><span>单例服务</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-3 collapsed ng-star-inserted" style="position:relative" href="guide/lazy-loading-ngmodules" title="惰性加载模块，以提高应用的性能" target="_self"><span>惰性加载的特性模块</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-3 collapsed ng-star-inserted" style="position:relative" href="guide/sharing-ngmodules" title="共享 NgModule 让你的应用现代化。" target="_self"><span>共享 NgModule</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-3 collapsed ng-star-inserted" style="position:relative" href="guide/ngmodule-api" title="理解 NgModule 的那些细节。" target="_self"><span>NgModule API</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-3 collapsed ng-star-inserted" style="position:relative" href="guide/ngmodule-faq" title="回答关于 NgModules 的常见问题。" target="_self"><span>NgModule 常见问题</span></a></div></aio-nav-item></div></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><button type="button" class="vertical-menu-item heading level-2 collapsed ng-star-inserted" title="依赖注入：创建并注入各种服务。" aria-pressed="false"><span>依赖注入</span><mat-icon role="img" svgicon="keyboard_arrow_right" class="mat-icon notranslate rotating-icon mat-icon-no-color" aria-hidden="true"><svg focusable="false" viewBox="0 0 24 24" xmlns="http://www.w3.org/2000/svg"><path d="M8.59 16.34l4.58-4.59-4.58-4.59L10 5.75l6 6-6 6z"></path></svg></mat-icon></button><div class="heading-children level-2 collapsed"><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-3 collapsed ng-star-inserted" style="position:relative" href="guide/dependency-injection" title="Angular 的依赖注入系统能够为 Angular 创建的类创建并交付它们所依赖的服务。" target="_self"><span>Angular 依赖注入</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-3 collapsed ng-star-inserted" style="position:relative" href="guide/hierarchical-dependency-injection" title="与组件树平行的注入器树，并支持嵌套的依赖。" target="_self"><span>多级注入器</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-3 collapsed ng-star-inserted" style="position:relative" href="guide/dependency-injection-providers" title="各种提供商类型的更多知识。" target="_self"><span>DI 提供商</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-3 collapsed ng-star-inserted" style="position:relative" href="guide/dependency-injection-in-action" title="依赖注入的使用技巧" target="_self"><span>DI 实战</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-3 collapsed ng-star-inserted" style="position:relative" href="guide/dependency-injection-navtree" title="使用注入器树来查找父组件。" target="_self"><span>浏览组件树</span></a></div></aio-nav-item></div></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-2 collapsed ng-star-inserted" style="position:relative" href="guide/http" title="通过 HTTP 协议与远程服务器对话。" target="_self"><span>HttpClient</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-2 collapsed ng-star-inserted" style="position:relative" href="guide/router" title="揭示如何通过 Angular 路由进行基本的屏幕导航。" target="_self"><span>路由与导航</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><button type="button" class="vertical-menu-item heading level-2 collapsed ng-star-inserted" title="Angular 动画系统指南" aria-pressed="false"><span>动画</span><mat-icon role="img" svgicon="keyboard_arrow_right" class="mat-icon notranslate rotating-icon mat-icon-no-color" aria-hidden="true"><svg focusable="false" viewBox="0 0 24 24" xmlns="http://www.w3.org/2000/svg"><path d="M8.59 16.34l4.58-4.59-4.58-4.59L10 5.75l6 6-6 6z"></path></svg></mat-icon></button><div class="heading-children level-2 collapsed"><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-3 collapsed ng-star-inserted" style="position:relative" href="guide/animations" title="Angular 动画的基础技术。" target="_self"><span>简介</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-3 collapsed ng-star-inserted" style="position:relative" href="guide/transition-and-triggers" title="转场与触发器的高级技术。" target="_self"><span>转场与触发器</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-3 collapsed ng-star-inserted" style="position:relative" href="guide/complex-animation-sequences" title="复杂的 Angular 动画序列。" target="_self"><span>复杂序列</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-3 collapsed ng-star-inserted" style="position:relative" href="guide/reusable-animations" title="创建可复用的动画。" target="_self"><span>可复用动画</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-3 collapsed ng-star-inserted" style="position:relative" href="guide/route-animations" title="为路由提供转场动画。" target="_self"><span>路由转场动画</span></a></div></aio-nav-item></div></div></aio-nav-item></div></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><button type="button" class="vertical-menu-item heading level-1 collapsed ng-star-inserted" title="把 Angular 用到你的实际工作中的一些技巧" aria-pressed="false"><span>其它技术</span><mat-icon role="img" svgicon="keyboard_arrow_right" class="mat-icon notranslate rotating-icon mat-icon-no-color" aria-hidden="true"><svg focusable="false" viewBox="0 0 24 24" xmlns="http://www.w3.org/2000/svg"><path d="M8.59 16.34l4.58-4.59-4.58-4.59L10 5.75l6 6-6 6z"></path></svg></mat-icon></button><div class="heading-children level-1 collapsed"><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-2 collapsed ng-star-inserted" style="position:relative" href="guide/security" title="Angular 应用开发中的安全技术。" target="_self"><span>安全</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-2 collapsed ng-star-inserted" style="position:relative" href="guide/i18n" title="把应用模板中的文本翻译成多种语言。" target="_self"><span>国际化（i18n）</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-2 collapsed ng-star-inserted" style="position:relative" href="guide/accessibility" title="设计能被所有用户访问的应用" target="_self"><span>无障碍（a11y）</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><button type="button" class="vertical-menu-item heading level-2 collapsed ng-star-inserted" title="Angular Service Worker: 控制应用资源的缓存。" aria-pressed="false"><span>Service Worker 与 PWA</span><mat-icon role="img" svgicon="keyboard_arrow_right" class="mat-icon notranslate rotating-icon mat-icon-no-color" aria-hidden="true"><svg focusable="false" viewBox="0 0 24 24" xmlns="http://www.w3.org/2000/svg"><path d="M8.59 16.34l4.58-4.59-4.58-4.59L10 5.75l6 6-6 6z"></path></svg></mat-icon></button><div class="heading-children level-2 collapsed"><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-3 collapsed ng-star-inserted" style="position:relative" href="guide/service-worker-intro" title="Angular 对 Service Worker 的实现提升了慢速或不稳定的网络连接下的用户体验。" target="_self"><span>简介</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-3 collapsed ng-star-inserted" style="position:relative" href="guide/service-worker-getting-started" title="在 CLI 项目中启用 Service Worker，并在浏览器中查看效果。" target="_self"><span>快速上手</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-3 collapsed ng-star-inserted" style="position:relative" href="guide/app-shell" title="在 CLI 项目中启用应用外壳。" target="_self"><span>应用外壳</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-3 collapsed ng-star-inserted" style="position:relative" href="guide/service-worker-communications" title="那些能让你和 Angular 的 Service Worker 通讯的服务类。" target="_self"><span>与 Service Worker 通讯</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-3 collapsed ng-star-inserted" style="position:relative" href="guide/service-worker-devops" title="使用 Service Worker 运行应用、管理应用更新、调试以及杀掉正在运行的应用。" target="_self"><span>生产环境下的 Service Worker</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-3 collapsed ng-star-inserted" style="position:relative" href="guide/service-worker-config" title="配置 Service Worker 的缓存行为。" target="_self"><span>Service Worker 配置</span></a></div></aio-nav-item></div></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-2 collapsed ng-star-inserted" style="position:relative" href="guide/universal" title="使用 Angular Universal 在服务端渲染 HTML。" target="_self"><span>服务端渲染</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><button type="button" class="vertical-menu-item heading level-2 collapsed ng-star-inserted" title="把 AngularJS 应用增量式的升级到 Angular。" aria-pressed="false"><span>从 AngularJS 升级</span><mat-icon role="img" svgicon="keyboard_arrow_right" class="mat-icon notranslate rotating-icon mat-icon-no-color" aria-hidden="true"><svg focusable="false" viewBox="0 0 24 24" xmlns="http://www.w3.org/2000/svg"><path d="M8.59 16.34l4.58-4.59-4.58-4.59L10 5.75l6 6-6 6z"></path></svg></mat-icon></button><div class="heading-children level-2 collapsed"><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-3 collapsed ng-star-inserted" style="position:relative" href="guide/upgrade" title="把 AngularJS 应用增量式的升级到 Angular。" target="_self"><span>升级步骤</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-3 collapsed ng-star-inserted" style="position:relative" href="guide/upgrade-performance" title="用更灵活的方式把 AngularJS 升级到 Angular。" target="_self"><span>更关注性能的升级方式</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-3 collapsed ng-star-inserted" style="position:relative" href="guide/ajs-quick-reference" title="学习如何把 AngularJS 的概念映射到 Angular 中。" target="_self"><span>AngularJS 与 Angular 的概念对照</span></a></div></aio-nav-item></div></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><button type="button" class="vertical-menu-item heading level-2 collapsed ng-star-inserted" title="使用共享库扩展 Angular" aria-pressed="false"><span>开发 Angular 库</span><mat-icon role="img" svgicon="keyboard_arrow_right" class="mat-icon notranslate rotating-icon mat-icon-no-color" aria-hidden="true"><svg focusable="false" viewBox="0 0 24 24" xmlns="http://www.w3.org/2000/svg"><path d="M8.59 16.34l4.58-4.59-4.58-4.59L10 5.75l6 6-6 6z"></path></svg></mat-icon></button><div class="heading-children level-2 collapsed"><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-3 collapsed ng-star-inserted" style="position:relative" href="guide/libraries" title="理解何时以及如何使用和创建库。" target="_self"><span>库概览</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-3 collapsed ng-star-inserted" style="position:relative" href="guide/using-libraries" title="把已发布的库集成进你的应用中。" target="_self"><span>使用已发布的库</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-3 collapsed ng-star-inserted" style="position:relative" href="guide/creating-libraries" title="通过创建、发布和使用你自己的库来扩展 Angular。" target="_self"><span>创建库</span></a></div></aio-nav-item></div></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><button type="button" class="vertical-menu-item heading level-2 collapsed ng-star-inserted" title="理解原理图" aria-pressed="false"><span>原理图（Schematic）</span><mat-icon role="img" svgicon="keyboard_arrow_right" class="mat-icon notranslate rotating-icon mat-icon-no-color" aria-hidden="true"><svg focusable="false" viewBox="0 0 24 24" xmlns="http://www.w3.org/2000/svg"><path d="M8.59 16.34l4.58-4.59-4.58-4.59L10 5.75l6 6-6 6z"></path></svg></mat-icon></button><div class="heading-children level-2 collapsed"><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-3 collapsed ng-star-inserted" style="position:relative" href="guide/schematics" title="理解 Angular 如何使用原理图。" target="_self"><span>原理图概览</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-3 collapsed ng-star-inserted" style="position:relative" href="guide/schematics-authoring" title="理解原理图的结构。" target="_self"><span>制作原理图</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-3 collapsed ng-star-inserted" style="position:relative" href="guide/schematics-for-libraries" title="使用原理图来把你的库集成进 Angular CLI 中。" target="_self"><span>库的原理图</span></a></div></aio-nav-item></div></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-2 collapsed ng-star-inserted" style="position:relative" href="guide/cli-builder" title="使用构建器定制 Angular CLI。" target="_self"><span>CLI 构建器</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-2 collapsed ng-star-inserted" style="position:relative" href="guide/web-worker" title="在 Angular CLI 中使用 Web Worker。" target="_self"><span>Web Worker</span></a></div></aio-nav-item></div></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><button type="button" class="vertical-menu-item heading level-1 collapsed ng-star-inserted" title="关于构建、测试和部署的信息" aria-pressed="false"><span>开发工作流</span><mat-icon role="img" svgicon="keyboard_arrow_right" class="mat-icon notranslate rotating-icon mat-icon-no-color" aria-hidden="true"><svg focusable="false" viewBox="0 0 24 24" xmlns="http://www.w3.org/2000/svg"><path d="M8.59 16.34l4.58-4.59-4.58-4.59L10 5.75l6 6-6 6z"></path></svg></mat-icon></button><div class="heading-children level-1 collapsed"><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><button type="button" class="vertical-menu-item heading level-2 collapsed ng-star-inserted" title="理解 AOT 预先编译器。" aria-pressed="false"><span>AOT 预先编译器</span><mat-icon role="img" svgicon="keyboard_arrow_right" class="mat-icon notranslate rotating-icon mat-icon-no-color" aria-hidden="true"><svg focusable="false" viewBox="0 0 24 24" xmlns="http://www.w3.org/2000/svg"><path d="M8.59 16.34l4.58-4.59-4.58-4.59L10 5.75l6 6-6 6z"></path></svg></mat-icon></button><div class="heading-children level-2 collapsed"><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-3 collapsed ng-star-inserted" style="position:relative" href="guide/aot-compiler" title="学习为何以及如何使用预先编译器。" target="_self"><span>预先编译</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-3 collapsed ng-star-inserted" style="position:relative" href="guide/angular-compiler-options" title="配置 AOT 编译。" target="_self"><span>Angular 编译器选项</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-3 collapsed ng-star-inserted" style="position:relative" href="guide/aot-metadata-errors" title="解决 AOT 编译错误。" target="_self"><span>AOT 元数据错误</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-3 collapsed ng-star-inserted" style="position:relative" href="guide/template-typecheck" title="Angular 中的模板类型检查。" target="_self"><span>模板类型检查</span></a></div></aio-nav-item></div></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-2 collapsed ng-star-inserted" style="position:relative" href="guide/build" title="构建应用及为应用启动开发服务器。" target="_self"><span>构建与运行</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-2 collapsed ng-star-inserted" style="position:relative" href="guide/bazel" title="如何配置你的环境，以利用 Bazel 进行构建和测试。" target="_self"><span>使用 Bazel 进行构建</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-2 collapsed ng-star-inserted" style="position:relative" href="guide/testing" title="测试 Angular 应用的技巧与实践。" target="_self"><span>测试</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-2 collapsed ng-star-inserted" style="position:relative" href="guide/deployment" title="了解如何部署 Angular 应用。" target="_self"><span>发布</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><button type="button" class="vertical-menu-item heading level-2 collapsed ng-star-inserted" title="与开发环境和工具集成起来" aria-pressed="false"><span>开发工具集成</span><mat-icon role="img" svgicon="keyboard_arrow_right" class="mat-icon notranslate rotating-icon mat-icon-no-color" aria-hidden="true"><svg focusable="false" viewBox="0 0 24 24" xmlns="http://www.w3.org/2000/svg"><path d="M8.59 16.34l4.58-4.59-4.58-4.59L10 5.75l6 6-6 6z"></path></svg></mat-icon></button><div class="heading-children level-2 collapsed"><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-3 collapsed ng-star-inserted" style="position:relative" href="guide/language-service" title="使用 Angular 语言服务加速开发。" target="_self"><span>语言服务</span></a></div></aio-nav-item></div></div></aio-nav-item></div></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><button type="button" class="vertical-menu-item heading level-1 collapsed ng-star-inserted" title="工作空间与项目的结构，及其配置文件。" aria-pressed="false"><span>配置</span><mat-icon role="img" svgicon="keyboard_arrow_right" class="mat-icon notranslate rotating-icon mat-icon-no-color" aria-hidden="true"><svg focusable="false" viewBox="0 0 24 24" xmlns="http://www.w3.org/2000/svg"><path d="M8.59 16.34l4.58-4.59-4.58-4.59L10 5.75l6 6-6 6z"></path></svg></mat-icon></button><div class="heading-children level-1 collapsed"><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-2 collapsed ng-star-inserted" style="position:relative" href="guide/file-structure" title="Angular 工作区在文件系统中是怎样的。" target="_self"><span>项目文件结构</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-2 collapsed ng-star-inserted" style="position:relative" href="guide/workspace-config" title="&quot;angular.json&quot; 包含供 CLI 命令使用的工作区和项目默认配置。" target="_self"><span>工作区配置</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-2 collapsed ng-star-inserted" style="position:relative" href="guide/npm-packages" title="开发期间和运行期间所需的 npm 包的说明。" target="_self"><span>npm 包</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-2 collapsed ng-star-inserted" style="position:relative" href="guide/typescript-configuration" title="给 Angular 开发者的 TypeScript 配置。" target="_self"><span>TypeScript 配置</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-2 collapsed ng-star-inserted" style="position:relative" href="guide/browser-support" title="浏览器支持与腻子脚本指南。" target="_self"><span>浏览器支持</span></a></div></aio-nav-item></div></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><button type="button" class="vertical-menu-item heading level-1 collapsed ng-star-inserted" title="Angular 的版本发布实践、更新与升级。" aria-pressed="false"><span>发布信息</span><mat-icon role="img" svgicon="keyboard_arrow_right" class="mat-icon notranslate rotating-icon mat-icon-no-color" aria-hidden="true"><svg focusable="false" viewBox="0 0 24 24" xmlns="http://www.w3.org/2000/svg"><path d="M8.59 16.34l4.58-4.59-4.58-4.59L10 5.75l6 6-6 6z"></path></svg></mat-icon></button><div class="heading-children level-1 collapsed"><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-2 collapsed ng-star-inserted" style="position:relative" href="guide/updating" title="如何把 Angular 应用和库升级到最新版本。" target="_self"><span>保持最新</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-2 collapsed ng-star-inserted" style="position:relative" href="guide/releases" title="Angular 的版本、发布、支持、弃用策略及实践。" target="_self"><span>发布实践</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-2 collapsed ng-star-inserted" style="position:relative" href="guide/updating-to-version-9" title="支持把你的应用从 8 升级到 9。" target="_self"><span>升级到第 9 版</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-2 collapsed ng-star-inserted" style="position:relative" href="guide/deprecations" title="弃用的 Angular API 和特性汇总。" target="_self"><span>弃用清单</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-2 collapsed ng-star-inserted" style="position:relative" href="guide/ivy" title="关于 Angular Ivy 的编译与渲染管道。" target="_self"><span>Angular Ivy</span></a></div></aio-nav-item></div></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><button type="button" class="vertical-menu-item heading level-1 collapsed ng-star-inserted" title="Angular 语法、编码、术语汇总。" aria-pressed="false"><span>快捷手册</span><mat-icon role="img" svgicon="keyboard_arrow_right" class="mat-icon notranslate rotating-icon mat-icon-no-color" aria-hidden="true"><svg focusable="false" viewBox="0 0 24 24" xmlns="http://www.w3.org/2000/svg"><path d="M8.59 16.34l4.58-4.59-4.58-4.59L10 5.75l6 6-6 6z"></path></svg></mat-icon></button><div class="heading-children level-1 collapsed"><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-2 collapsed ng-star-inserted" style="position:relative" href="guide/cheatsheet" title="关于 Angular 常用编码技术的快速指南。" target="_self"><span>速查表</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-2 collapsed ng-star-inserted" style="position:relative" href="guide/styleguide" title="写出 Angular 风格的程序" target="_self"><span>风格指南</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-2 collapsed ng-star-inserted" style="position:relative" href="guide/glossary" title="Angular 中最重要的词汇的简要定义。" target="_self"><span>词汇表</span></a></div></aio-nav-item></div></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><button type="button" class="vertical-menu-item heading level-1 collapsed ng-star-inserted" title="Angular CLI 命令参考手册。" aria-pressed="false"><span>CLI 命令</span><mat-icon role="img" svgicon="keyboard_arrow_right" class="mat-icon notranslate rotating-icon mat-icon-no-color" aria-hidden="true"><svg focusable="false" viewBox="0 0 24 24" xmlns="http://www.w3.org/2000/svg"><path d="M8.59 16.34l4.58-4.59-4.58-4.59L10 5.75l6 6-6 6z"></path></svg></mat-icon></button><div class="heading-children level-1 collapsed"><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-2 collapsed ng-star-inserted" style="position:relative" href="cli" title="CLI 工具介绍、命令、语法" target="_self"><span>概览</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-2 collapsed ng-star-inserted" style="position:relative" href="cli/usage-analytics-gathering" title="管理员如何从用户那里收集使用情况分析。" target="_self"><span>使用情况分析</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-2 collapsed ng-star-inserted" style="position:relative" href="cli/add" title="ng add." target="_self"><span>ng add</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-2 collapsed ng-star-inserted" style="position:relative" href="cli/analytics" title="ng analytics." target="_self"><span>ng analytics</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-2 collapsed ng-star-inserted" style="position:relative" href="cli/build" title="ng build." target="_self"><span>ng build</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-2 collapsed ng-star-inserted" style="position:relative" href="cli/config" title="ng config." target="_self"><span>ng config</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-2 collapsed ng-star-inserted" style="position:relative" href="cli/deploy" title="ng deploy." target="_self"><span>ng deploy</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-2 collapsed ng-star-inserted" style="position:relative" href="cli/doc" title="ng doc." target="_self"><span>ng doc</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-2 collapsed ng-star-inserted" style="position:relative" href="cli/e2e" title="ng e2e." target="_self"><span>ng e2e</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-2 collapsed ng-star-inserted" style="position:relative" href="cli/generate" title="ng generate." target="_self"><span>ng generate</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-2 collapsed ng-star-inserted" style="position:relative" href="cli/help" title="ng help." target="_self"><span>ng help</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-2 collapsed ng-star-inserted" style="position:relative" href="cli/lint" title="ng lint." target="_self"><span>ng lint</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-2 collapsed ng-star-inserted" style="position:relative" href="cli/new" title="ng new." target="_self"><span>ng new</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-2 collapsed ng-star-inserted" style="position:relative" href="cli/run" title="ng run." target="_self"><span>ng run</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-2 collapsed ng-star-inserted" style="position:relative" href="cli/serve" title="ng serve." target="_self"><span>ng serve</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-2 collapsed ng-star-inserted" style="position:relative" href="cli/test" title="ng test." target="_self"><span>ng test</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div 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参考手册</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><div class="mat-divider ng-star-inserted" style="margin:4px 20px;border-top:1px solid #d3d3d3"></div></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-1 collapsed ng-star-inserted" style="position:relative" href="https://github.com/ng-docs/ng-docs.github.io/issues" title="github 上的中文互助问答区" target="_blank"><span>互助问答</span><mat-icon role="img" class="mat-icon notranslate material-icons mat-icon-no-color ng-star-inserted" aria-hidden="true">open_in_new</mat-icon></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-1 collapsed ng-star-inserted" style="position:relative" href="https://material.angular.cn" title="Angular Material 组件库的中文文档" target="_blank"><span>官方 Material 组件库</span><mat-icon role="img" class="mat-icon notranslate material-icons mat-icon-no-color ng-star-inserted" aria-hidden="true">open_in_new</mat-icon></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-1 collapsed ng-star-inserted" style="position:relative" href="https://ng.ant.design/" title="Ant Design 的 Angular 实现，服务于企业级后台产品。" target="_blank"><span>ng-zorro 组件库</span><mat-icon role="img" class="mat-icon notranslate material-icons mat-icon-no-color ng-star-inserted" aria-hidden="true">open_in_new</mat-icon></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-1 collapsed ng-star-inserted" style="position:relative" href="https://ng.mobile.ant.design/" title="Ant Design Mobile 的 Angular 实现，服务于无线产品。" target="_blank"><span>ng-zorro mobile 组件库</span><mat-icon role="img" class="mat-icon notranslate material-icons mat-icon-no-color ng-star-inserted" aria-hidden="true">open_in_new</mat-icon></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-1 collapsed ng-star-inserted" style="position:relative" href="https://flutter-io.cn/" title="Flutter 中文文档站" target="_blank"><span>友站：Flutter 中文</span><mat-icon role="img" class="mat-icon notranslate material-icons mat-icon-no-color ng-star-inserted" aria-hidden="true">open_in_new</mat-icon></a></div></aio-nav-item></aio-nav-menu><div class="doc-version ng-tns-c18-1"><aio-select><div class="form-select-menu"><button class="form-select-button"><span><strong></strong></span><span>stable (v9.0.0)</span></button></div></aio-select></div></div></mat-sidenav><div class="cdk-visually-hidden cdk-focus-trap-anchor" aria-hidden="true"></div><mat-sidenav-content cdkscrollable="" class="mat-drawer-content mat-sidenav-content ng-star-inserted" style="margin-left:261px"><main role="main" class="sidenav-content" id="guide-elements"><aio-mode-banner></aio-mode-banner><aio-doc-viewer class=""><div style="opacity:1"><div class="github-links"><a href="https://github.com/angular/angular-cn/edit/aio/aio/content/guide/elements.md?message=docs%3A%20请简述你的修改..." aria-label="提供编辑建议" title="提供编辑建议"><i class="material-icons" aria-hidden="true" role="img">mode_edit</i></a></div><div class="content"><h1 id="angular-elements-overview" translation-result="on">Angular 元素（Elements）概览<a title="Link to this heading" class="header-link" aria-hidden="true" href="guide/elements#angular-elements-overview"><i class="material-icons">link</i></a></h1><aio-toc class="embedded" ng-version="9.0.0-rc.11"><div class="toc-inner no-print collapsed ng-star-inserted"><button type="button" title="Expand/collapse contents" aria-label="Expand/collapse contents" class="toc-heading embedded secondary ng-star-inserted" aria-pressed="false">目录<mat-icon role="img" svgicon="keyboard_arrow_right" class="mat-icon notranslate rotating-icon collapsed mat-icon-no-color" aria-hidden="true"><svg focusable="false" viewBox="0 0 24 24" xmlns="http://www.w3.org/2000/svg"><path d="M8.59 16.34l4.58-4.59-4.58-4.59L10 5.75l6 6-6 6z"></path></svg></mat-icon></button><ul class="toc-list embedded"><li class="h2 ng-star-inserted" title="使用自定义元素"><a href="guide/elements#using-custom-elements">使用自定义元素</a></li><li class="h3 ng-star-inserted" title="工作原理"><a href="guide/elements#how-it-works">工作原理</a></li><li class="h2 ng-star-inserted" title="把组件转换成自定义元素"><a href="guide/elements#transforming-components-to-custom-elements">把组件转换成自定义元素</a></li><li class="h3 secondary ng-star-inserted" title="映射"><a href="guide/elements#mapping">映射</a></li><li class="h2 secondary ng-star-inserted" title="自定义元素的浏览器支持"><a href="guide/elements#browser-support-for-custom-elements">自定义元素的浏览器支持</a></li><li class="h2 secondary ng-star-inserted" title="范例：弹窗服务"><a href="guide/elements#example-a-popup-service">范例：弹窗服务</a></li><li class="h2 secondary ng-star-inserted" title="为自定义元素添加类型支持"><a href="guide/elements#typings-for-custom-elements">为自定义元素添加类型支持</a></li></ul><button type="button" title="Expand/collapse contents" aria-label="Expand/collapse contents" class="toc-more-items embedded material-icons collapsed ng-star-inserted" aria-pressed="false"></button></div></aio-toc><h1 translation-origin="off" id="angular-elements-overview">Angular elements overview<a title="Link to this heading" class="header-link" aria-hidden="true" href="guide/elements#angular-elements-overview"><i class="material-icons">link</i></a></h1><p translation-result="on"><em>Angular 元素</em>就是打包成<em>自定义元素</em>的 Angular 组件。所谓自定义元素就是一套与具体框架无关的用于定义新 HTML 元素的 Web 标准。</p><p translation-origin="off"><em>Angular elements</em> are Angular components packaged as <em>custom elements</em> (also called Web Components), a web standard for defining new HTML elements in a framework-agnostic way.</p><p translation-result="on"><a href="https://developer.mozilla.org/en-US/docs/Web/Web_Components/Using_custom_elements">自定义元素</a>这项特性目前受到了 Chrome、Opera 和 Safari 的支持，在其它浏览器中也能通过腻子脚本（参见<a href="guide/elements#browser-support">浏览器支持</a>）加以支持。 自定义元素扩展了 HTML，它允许你定义一个由 JavaScript 代码创建和控制的标签。 浏览器会维护一个自定义元素的注册表 <code>CustomElementRegistry</code>，它把一个可实例化的 JavaScript 类映射到 HTML 标签上。</p><p translation-origin="off"><a href="https://developer.mozilla.org/en-US/docs/Web/Web_Components/Using_custom_elements">Custom elements</a> are a Web Platform feature currently supported by Chrome, Firefox, Opera, and Safari, and available in other browsers through polyfills (see <a href="guide/elements#browser-support">Browser Support</a>). A custom element extends HTML by allowing you to define a tag whose content is created and controlled by JavaScript code. The browser maintains a <code>CustomElementRegistry</code> of defined custom elements, which maps an instantiable JavaScript class to an HTML tag.</p><p translation-result="on"><code>@angular/elements</code> 包导出了一个 <code><a href="api/elements/createCustomElement" class="code-anchor">createCustomElement</a>()</code> API，它在 Angular 组件接口与变更检测功能和内置 DOM API 之间建立了一个桥梁。</p><p translation-origin="off">The <code>@angular/elements</code> package exports a <code><a href="api/elements/createCustomElement" class="code-anchor">createCustomElement</a>()</code> API that provides a bridge from Angular's component interface and change detection functionality to the built-in DOM API.</p><p translation-result="on">把组件转换成自定义元素可以让所有所需的 Angular 基础设施都在浏览器中可用。 创建自定义元素的方式简单直观，它会自动把你组件定义的视图连同变更检测与数据绑定等 Angular 的功能映射为相应的原生 HTML 等价物。</p><p translation-origin="off">Transforming a component to a custom element makes all of the required Angular infrastructure available to the browser. Creating a custom element is simple and straightforward, and automatically connects your component-defined view with change detection and data binding, mapping Angular functionality to the corresponding native HTML equivalents.</p><div class="alert is-helpful"><p translation-result="on">我们正在持续开发自定义元素功能，让它们可以用在由其它框架所构建的 Web 应用中。 Angular 框架的一个小型的、自包含的版本将会作为服务注入进去，以提供组件的变更检测和数据绑定功能。 要了解这个开发方向的更多内容，参见<a href="https://www.youtube.com/watch?v=Z1gLFPLVJjY&amp;t=4s">这个视频演讲</a>。</p><p translation-origin="off">We are working on custom elements that can be used by web apps built on other frameworks. A minimal, self-contained version of the Angular framework will be injected as a service to support the component's change-detection and data-binding functionality. For more about the direction of development, check out this <a href="https://www.youtube.com/watch?v=Z1gLFPLVJjY&amp;t=4s">video presentation</a>.</p></div><h2 id="using-custom-elements" translation-result="on">使用自定义元素<a title="Link to this heading" class="header-link" aria-hidden="true" href="guide/elements#using-custom-elements"><i class="material-icons">link</i></a></h2><h2 translation-origin="off" id="using-custom-elements">Using custom elements<a title="Link to this heading" class="header-link" aria-hidden="true" href="guide/elements#using-custom-elements"><i class="material-icons">link</i></a></h2><p translation-result="on">自定义元素会自举启动 —— 它们在添加到 DOM 中时就会自行启动自己，并在从 DOM 中移除时自行销毁自己。一旦自定义元素添加到了任何页面的 DOM 中，它的外观和行为就和其它的 HTML 元素一样了，不需要对 Angular 的术语或使用约定有任何特殊的了解。</p><p translation-origin="off">Custom elements bootstrap themselves - they start automatically when they are added to the DOM, and are automatically destroyed when removed from the DOM. Once a custom element is added to the DOM for any page, it looks and behaves like any other HTML element, and does not require any special knowledge of Angular terms or usage conventions.</p><ul><li><p translation-result="on"><b>Angular 应用中的简易动态内容</b></p><p translation-origin="off"><b>Easy dynamic content in an Angular app</b></p><p translation-result="on">把组件转换成自定义元素为你在 Angular 应用中创建动态 HTML 内容提供了一种简单的方式。 在 Angular 应用中，你直接添加到 DOM 中的 HTML 内容是不会经过 Angular 处理的，除非你使用<em>动态组件</em>来借助自己的代码把 HTML 标签与你的应用数据关联起来并参与变更检测。而使用自定义组件，所有这些装配工作都是自动的。</p><p translation-origin="off">Transforming a component to a custom element provides an easy path to creating dynamic HTML content in your Angular app. HTML content that you add directly to the DOM in an Angular app is normally displayed without Angular processing, unless you define a <em>dynamic component</em>, adding your own code to connect the HTML tag to your app data, and participate in change detection. With a custom element, all of that wiring is taken care of automatically.</p></li><li><p translation-result="on"><b>富内容应用</b></p><p translation-origin="off"><b>Content-rich applications</b></p><p translation-result="on">如果你有一个富内容应用（比如正在展示本文档的这个），自定义元素能让你的内容提供者使用复杂的 Angular 功能，而不要求他了解 Angular 的知识。比如，像本文档这样的 Angular 指南是使用 Angular 导航工具直接添加到 DOM 中的，但是其中可以包含特殊的元素，比如 <code>&lt;code-snippet&gt;</code>，它可以执行复杂的操作。 你所要告诉你的内容提供者的一切，就是这个自定义元素的语法。他们不需要了解关于 Angular 的任何知识，也不需要了解你的组件的数据结构或实现。</p><p translation-origin="off">If you have a content-rich app, such as the Angular app that presents this documentation, custom elements let you give your content providers sophisticated Angular functionality without requiring knowledge of Angular. For example, an Angular guide like this one is added directly to the DOM by the Angular navigation tools, but can include special elements like <code>&lt;code-snippet&gt;</code> that perform complex operations. All you need to tell your content provider is the syntax of your custom element. They don't need to know anything about Angular, or anything about your component's data structures or implementation.</p></li></ul><h3 id="how-it-works" translation-result="on">工作原理<a title="Link to this heading" class="header-link" aria-hidden="true" href="guide/elements#how-it-works"><i class="material-icons">link</i></a></h3><h3 translation-origin="off" id="how-it-works">How it works<a title="Link to this heading" class="header-link" aria-hidden="true" href="guide/elements#how-it-works"><i class="material-icons">link</i></a></h3><p translation-result="on">使用 <code><a href="api/elements/createCustomElement" class="code-anchor">createCustomElement</a>()</code> 函数来把组件转换成一个可注册成浏览器中自定义元素的类。 注册完这个配置好的类之后，你就可以在内容中像内置 HTML 元素一样使用这个新元素了，比如直接把它加到 DOM 中：</p><p translation-origin="off">Use the <code><a href="api/elements/createCustomElement" class="code-anchor">createCustomElement</a>()</code> function to convert a component into a class that can be registered with the browser as a custom element. After you register your configured class with the browser's custom-element registry, you can use the new element just like a built-in HTML element in content that you add directly into the DOM:</p><code-example ng-version="9.0.0-rc.11"><div style="display:none">&lt;my-popup <a href="api/common/http/HttpErrorResponse#message" class="code-anchor">message</a>="Use Angular!"&gt;&lt;/my-popup&gt;</div><aio-code><pre class="lang- prettyprint">      <button title="Copy code snippet" class="material-icons copy-button no-print ng-star-inserted" aria-label="">
        <span aria-hidden="true">content_copy</span>
      </button>
      <code class="animated fadeIn"><span class="tag">&lt;my-popup</span><span class="pln"> </span><a href="api/common/http/HttpErrorResponse#message" class="code-anchor"><span class="atn">message</span></a><span class="pun">=</span><span class="atv">"Use Angular!"</span><span class="tag">&gt;&lt;/my-popup&gt;</span></code>
    </pre></aio-code></code-example><p translation-result="on">当你的自定义元素放进页面中时，浏览器会创建一个已注册类的实例。其内容是由组件模板提供的，它使用 Angular 模板语法，并且使用组件和 DOM 数据进行渲染。组件的输入属性（Property）对应于该元素的输入属性（Attribute）。</p><p translation-origin="off">When your custom element is placed on a page, the browser creates an instance of the registered class and adds it to the DOM. The content is provided by the component's template, which uses Angular template syntax, and is rendered using the component and DOM data. Input properties in the component correspond to input attributes for the element.</p><div class="lightbox"><img src="generated/images/guide/elements/customElement1.png" alt="Custom element in browser" class="left" width="600" height="360"></div><hr class="clear"><h2 id="transforming-components-to-custom-elements" translation-result="on">把组件转换成自定义元素<a title="Link to this heading" class="header-link" aria-hidden="true" href="guide/elements#transforming-components-to-custom-elements"><i class="material-icons">link</i></a></h2><h2 translation-origin="off" id="transforming-components-to-custom-elements">Transforming components to custom elements<a title="Link to this heading" class="header-link" aria-hidden="true" href="guide/elements#transforming-components-to-custom-elements"><i class="material-icons">link</i></a></h2><p translation-result="on">Angular 提供了 <code><a href="api/elements/createCustomElement" class="code-anchor">createCustomElement</a>()</code> 函数，以支持把 Angular 组件及其依赖转换成自定义元素。该函数会收集该组件的 <code>Observable</code> 型属性，提供浏览器创建和销毁实例时所需的 Angular 功能，还会对变更进行检测并做出响应。</p><p translation-origin="off">Angular provides the <code><a href="api/elements/createCustomElement" class="code-anchor">createCustomElement</a>()</code> function for converting an Angular component, together with its dependencies, to a custom element. The function collects the component's observable properties, along with the Angular functionality the browser needs to create and destroy instances, and to detect and respond to changes.</p><p translation-result="on">这个转换过程实现了 <code><a href="api/elements/NgElementConstructor" class="code-anchor">NgElementConstructor</a></code> 接口，并创建了一个构造器类，用于生成该组件的一个自举型实例。</p><p translation-origin="off">The conversion process implements the <code><a href="api/elements/NgElementConstructor" class="code-anchor">NgElementConstructor</a></code> interface, and creates a constructor class that is configured to produce a self-bootstrapping instance of your component.</p><p translation-result="on">然后用 JavaScript 的 <code>customElements.define()</code> 函数把这个配置好的构造器和相关的自定义元素标签注册到浏览器的 <code>CustomElementRegistry</code> 中。 当浏览器遇到这个已注册元素的标签时，就会使用该构造器来创建一个自定义元素的实例。</p><p translation-origin="off">Use a JavaScript function, <code>customElements.define()</code>, to register the configured constructor and its associated custom-element tag with the browser's <code>CustomElementRegistry</code>. When the browser encounters the tag for the registered element, it uses the constructor to create a custom-element instance.</p><div class="lightbox"><img src="generated/images/guide/elements/createElement.png" alt="Transform a component to a custom element" class="left" width="600" height="387"></div><h3 id="mapping" translation-result="on">映射<a title="Link to this heading" class="header-link" aria-hidden="true" href="guide/elements#mapping"><i class="material-icons">link</i></a></h3><h3 translation-origin="off" id="mapping">Mapping<a title="Link to this heading" class="header-link" aria-hidden="true" href="guide/elements#mapping"><i class="material-icons">link</i></a></h3><p translation-result="on"><em>寄宿</em>着 Angular 组件的自定义元素在组件中定义的"数据及逻辑"和标准的 DOM API 之间建立了一座桥梁。组件的属性和逻辑会直接映射到 HTML 属性和浏览器的事件系统中。</p><p translation-origin="off">A custom element <em>hosts</em> an Angular component, providing a bridge between the data and logic defined in the component and standard DOM APIs. Component properties and logic maps directly into HTML attributes and the browser's event system.</p><ul><li><p translation-result="on">用于创建的 API 会解析该组件，以查找输入属性（Property），并在这个自定义元素上定义相应的属性（Attribute）。 它把属性名转换成与自定义元素兼容的形式（自定义元素不区分大小写），生成的属性名会使用中线分隔的小写形式。 比如，对于带有 <code>@<a href="api/core/Input" class="code-anchor">Input</a>('myInputProp') inputProp</code> 的组件，其对应的自定义元素会带有一个 <code>my-input-prop</code> 属性。</p><p translation-origin="off">The creation API parses the component looking for input properties, and defines corresponding attributes for the custom element. It transforms the property names to make them compatible with custom elements, which do not recognize case distinctions. The resulting attribute names use dash-separated lowercase. For example, for a component with <code>@<a href="api/core/Input" class="code-anchor">Input</a>('myInputProp') inputProp</code>, the corresponding custom element defines an attribute <code>my-input-prop</code>.</p></li><li><p translation-result="on">组件的输出属性会用 HTML <a href="https://developer.mozilla.org/en-US/docs/Web/API/CustomEvent">自定义事件</a>的形式进行分发，自定义事件的名字就是这个输出属性的名字。 比如，对于带有 <code>@<a href="api/core/Output" class="code-anchor">Output</a>() valueChanged = new <a href="api/core/EventEmitter" class="code-anchor">EventEmitter</a>()</code> 属性的组件，其相应的自定义元素将会分发名叫 "valueChanged" 的事件，事件中所携带的数据存储在该事件对象的 <code>detail</code> 属性中。 如果你提供了别名，就改用这个别名。比如，<code>@<a href="api/core/Output" class="code-anchor">Output</a>('myClick') clicks = new <a href="api/core/EventEmitter" class="code-anchor">EventEmitter</a>&lt;string&gt;();</code> 会导致分发名为 "myClick" 事件。</p><p translation-origin="off">Component outputs are dispatched as HTML <a href="https://developer.mozilla.org/en-US/docs/Web/API/CustomEvent">Custom Events</a>, with the name of the custom event matching the output name. For example, for a component with <code>@<a href="api/core/Output" class="code-anchor">Output</a>() valueChanged = new <a href="api/core/EventEmitter" class="code-anchor">EventEmitter</a>()</code>, the corresponding custom element will dispatch events with the name "valueChanged", and the emitted data will be stored on the event’s <code>detail</code> property. If you provide an alias, that value is used; for example, <code>@<a href="api/core/Output" class="code-anchor">Output</a>('myClick') clicks = new <a href="api/core/EventEmitter" class="code-anchor">EventEmitter</a>&lt;string&gt;();</code> results in dispatch events with the name "myClick".</p></li></ul><p translation-result="on">要了解更多，请参见 Web Components 的文档：<a href="https://developer.mozilla.org/en-US/docs/Web/Guide/Events/Creating_and_triggering_events#Creating_custom_events">Creating custom events</a>。</p><p translation-origin="off">For more information, see Web Component documentation for <a href="https://developer.mozilla.org/en-US/docs/Web/Guide/Events/Creating_and_triggering_events#Creating_custom_events">Creating custom events</a>.</p><a id="browser-support"></a><h2 id="browser-support-for-custom-elements" translation-result="on">自定义元素的浏览器支持<a title="Link to this heading" class="header-link" aria-hidden="true" href="guide/elements#browser-support-for-custom-elements"><i class="material-icons">link</i></a></h2><h2 translation-origin="off" id="browser-support-for-custom-elements">Browser support for custom elements<a title="Link to this heading" class="header-link" aria-hidden="true" href="guide/elements#browser-support-for-custom-elements"><i class="material-icons">link</i></a></h2><p translation-result="on">最近开发的 Web 平台特性：<a href="https://developer.mozilla.org/en-US/docs/Web/Web_Components/Using_custom_elements">自定义元素</a>目前在一些浏览器中实现了原生支持，而其它浏览器或者尚未决定，或者已经制订了计划。</p><p translation-origin="off">The recently-developed <a href="https://developer.mozilla.org/en-US/docs/Web/Web_Components/Using_custom_elements">custom elements</a> Web Platform feature is currently supported natively in a number of browsers. Support is pending or planned in other browsers.</p><table><tbody><tr><th><p translation-result="on">浏览器</p><p translation-origin="off">Browser</p></th><th><p translation-result="on">自定义元素支持</p><p translation-origin="off">Custom Element Support</p></th></tr><tr><td><p>Chrome</p></td><td><p translation-result="on">原生支持。</p><p translation-origin="off">Supported natively.</p></td></tr><tr><td><p>Opera</p></td><td><p translation-result="on">原生支持。</p><p translation-origin="off">Supported natively.</p></td></tr><tr><td><p>Safari</p></td><td><p translation-result="on">原生支持。</p><p translation-origin="off">Supported natively.</p></td></tr><tr><td>Firefox</td><td><p translation-result="on">原生支持。</p><p translation-origin="off">Supported natively.</p></td></tr><tr><td><p>Edge</p></td><td><p translation-result="on">正在实现。<br></p><p translation-origin="off">Working on an implementation.<br></p></td></tr></tbody></table><p translation-result="on">对于原生支持了自定义元素的浏览器，该规范要求开发人员使用 ES2016 的类来定义自定义元素 —— 开发人员可以在项目的 <code>tsconfig.json</code> 中设置 <code>target: "es2015"</code> 属性来满足这一要求。并不是所有浏览器都支持自定义元素和 ES2015，开发人员也可以选择使用腻子脚本来让它支持老式浏览器和 ES5 的代码。</p><p translation-origin="off">In browsers that support Custom Elements natively, the specification requires developers use ES2015 classes to define Custom Elements - developers can opt-in to this by setting the <code>target: "es2015"</code> property in their project's <code>tsconfig.json</code>. As Custom Element and ES2015 support may not be available in all browsers, developers can instead choose to use a polyfill to support older browsers and ES5 code.</p><p translation-result="on">使用 <a href="https://cli.angular.io/">Angular CLI</a> 可以自动为你的项目添加正确的腻子脚本：<code>ng add @angular/elements --name=*your_project_name*</code>。</p><p translation-origin="off">Use the <a href="cli">Angular CLI</a> to automatically set up your project with the correct polyfill: <code>ng add @angular/elements --name=*your_project_name*</code>.</p><ul><li><p translation-result="on">要了解关于腻子脚本的更多信息，参见<a href="https://www.webcomponents.org/polyfills">腻子脚本的相关文档</a>。</p><p translation-origin="off">For more information about polyfills, see <a href="https://www.webcomponents.org/polyfills">polyfill documentation</a>.</p></li><li><p translation-result="on">要了解 Angular 浏览器支持的更多信息，参见<a href="guide/browser-support">浏览器支持</a>。</p><p translation-origin="off">For more information about Angular browser support, see <a href="guide/browser-support">Browser Support</a>.</p></li></ul><h2 id="example-a-popup-service" translation-result="on">范例：弹窗服务<a title="Link to this heading" class="header-link" aria-hidden="true" href="guide/elements#example-a-popup-service"><i class="material-icons">link</i></a></h2><h2 translation-origin="off" id="example-a-popup-service">Example: A Popup Service<a title="Link to this heading" class="header-link" aria-hidden="true" href="guide/elements#example-a-popup-service"><i class="material-icons">link</i></a></h2><p translation-result="on">以前，如果你要在运行期间把一个组件添加到应用中，就不得不定义<em>动态组件</em>。你还要把动态组件添加到模块的 <code>entryComponents</code> 列表中，以便应用在启动时能找到它，然后还要加载它、把它附加到 DOM 中的元素上，并且装配所有的依赖、变更检测和事件处理，详见<a href="guide/dynamic-component-loader">动态组件加载器</a>。</p><p translation-origin="off">Previously, when you wanted to add a component to an app at runtime, you had to define a <em>dynamic component</em>. The app module would have to list your dynamic component under <code>entryComponents</code>, so that the app wouldn't expect it to be present at startup, and then you would have to load it, attach it to an element in the DOM, and wire up all of the dependencies, change detection, and event handling, as described in <a href="guide/dynamic-component-loader">Dynamic Component Loader</a>.</p><p translation-result="on">用 Angular 自定义组件会让这个过程更简单、更透明。它会自动提供所有基础设施和框架，而你要做的就是定义所需的各种事件处理逻辑。（如果你不准备在应用中直接用它，还要把该组件在编译时排除出去。）</p><p translation-origin="off">Using an Angular custom element makes the process much simpler and more transparent, by providing all of the infrastructure and framework automatically—all you have to do is define the kind of event handling you want. (You do still have to exclude the component from compilation, if you are not going to use it in your app.)</p><p translation-result="on">这个弹窗服务的范例应用（见后面）定义了一个组件，你可以动态加载它也可以把它转换成自定义组件。</p><p translation-origin="off">The Popup Service example app (shown below) defines a component that you can either load dynamically or convert to a custom element.</p><ul><li><p translation-result="on"> <code>popup.component.ts</code> 定义了一个简单的弹窗元素，用于显示一条输入消息，附带一些动画和样式。</p><p translation-origin="off"><code>popup.component.ts</code> defines a simple pop-up element that displays an input message, with some animation and styling.</p></li><li><p translation-result="on"> <code>popup.service.ts</code> 创建了一个可注入的服务，它提供了两种方式来执行 PopupComponent：作为动态组件或作为自定义元素。注意动态组件的方式需要更多的代码来做搭建工作。</p><p translation-origin="off"><code>popup.service.ts</code> creates an injectable service that provides two different ways to invoke the PopupComponent; as a dynamic component, or as a custom element. Notice how much more setup is required for the dynamic-loading method.</p></li><li><p translation-result="on"> <code>app.module.ts</code> 把 PopupComponent 添加到模块的 <code>entryComponents</code> 列表中，而从编译过程中排除它，以消除启动时的警告和错误。</p><p translation-origin="off"><code>app.module.ts</code> adds the PopupComponent in the module's <code>entryComponents</code> list, to exclude it from compilation and avoid startup warnings or errors.</p></li><li><p translation-result="on"> <code>app.component.ts</code> 定义了该应用的根组件，它借助 PopupService 在运行时把这个弹窗添加到 DOM 中。在应用运行期间，根组件的构造函数会把 PopupComponent 转换成自定义元素。</p><p translation-origin="off"><code>app.component.ts</code> defines the app's root component, which uses the PopupService to add the pop-up to the DOM at run time. When the app runs, the root component's constructor converts PopupComponent to a custom element.</p></li></ul><p translation-result="on">为了对比，这个范例中同时演示了这两种方式。一个按钮使用动态加载的方式添加弹窗，另一个按钮使用自定义元素的方式。可以看到，两者的结果是一样的，其差别只是准备过程不同。</p><p translation-origin="off">For comparison, the demo shows both methods. One button adds the popup using the dynamic-loading method, and the other uses the custom element. You can see that the result is the same; only the preparation is different.</p><code-tabs ng-version="9.0.0-rc.11"><div style="display:none"><code-pane header="popup.component.ts" path="elements/src/app/popup.component.ts">import { <a href="api/core/Component" class="code-anchor">Component</a>, <a href="api/core/EventEmitter" class="code-anchor">EventEmitter</a>, <a href="api/core/Input" class="code-anchor">Input</a>, <a href="api/core/Output" class="code-anchor">Output</a> } from '@angular/core'; import { <a href="api/animations/animate" class="code-anchor">animate</a>, <a href="api/animations/state" class="code-anchor">state</a>, <a href="api/animations/style" class="code-anchor">style</a>, <a href="api/animations/transition" class="code-anchor">transition</a>, <a href="api/animations/trigger" class="code-anchor">trigger</a> } from '@angular/animations'; @<a href="api/core/Component" class="code-anchor">Component</a>({ selector: 'my-popup', template: ` &lt;span&gt;Popup: {{<a href="api/common/http/HttpErrorResponse#message" class="code-anchor">message</a>}}&lt;/span&gt; &lt;button (click)="closed.next()"&gt;&amp;#x2716;&lt;/button&gt; `, <a href="api/core/Directive#host" class="code-anchor">host</a>: { '[@<a href="api/animations/state" class="code-anchor">state</a>]': '<a href="api/animations/state" class="code-anchor">state</a>', }, animations: [ <a href="api/animations/trigger" class="code-anchor">trigger</a>('<a href="api/animations/state" class="code-anchor">state</a>', [ <a href="api/animations/state" class="code-anchor">state</a>('opened', <a href="api/animations/style" class="code-anchor">style</a>({transform: 'translateY(0%)'})), <a href="api/animations/state" class="code-anchor">state</a>('void, closed', <a href="api/animations/style" class="code-anchor">style</a>({transform: 'translateY(100%)', opacity: 0})), <a href="api/animations/transition" class="code-anchor">transition</a>('* =&gt; *', <a href="api/animations/animate" class="code-anchor">animate</a>('100ms ease-in')), ]) ], styles: [` :<a href="api/core/Directive#host" class="code-anchor">host</a> { <a href="api/router/Scroll#position" class="code-anchor">position</a>: absolute; bottom: 0; left: 0; right: 0; background: #009cff; height: 48px; padding: 16px; display: flex; justify-content: space-between; align-items: center; border-top: 1px solid black; font-size: 24px; } button { border-radius: 50%; } `] }) export class PopupComponent { private <a href="api/animations/state" class="code-anchor">state</a>: 'opened' | 'closed' = 'closed'; @<a href="api/core/Input" class="code-anchor">Input</a>() set <a href="api/common/http/HttpErrorResponse#message" class="code-anchor">message</a>(<a href="api/common/http/HttpErrorResponse#message" class="code-anchor">message</a>: string) { this._message = <a href="api/common/http/HttpErrorResponse#message" class="code-anchor">message</a>; this.state = 'opened'; } get <a href="api/common/http/HttpErrorResponse#message" class="code-anchor">message</a>(): string { return this._message; } _message: string; @<a href="api/core/Output" class="code-anchor">Output</a>() closed = new <a href="api/core/EventEmitter" class="code-anchor">EventEmitter</a>(); }</code-pane><code-pane header="popup.service.ts" path="elements/src/app/popup.service.ts">import { <a href="api/core/ApplicationRef" class="code-anchor">ApplicationRef</a>, <a href="api/core/ComponentFactoryResolver" class="code-anchor">ComponentFactoryResolver</a>, <a href="api/core/Injectable" class="code-anchor">Injectable</a>, <a href="api/core/Injector" class="code-anchor">Injector</a> } from '@angular/core'; import { <a href="api/elements/NgElement" class="code-anchor">NgElement</a>, <a href="api/elements/WithProperties" class="code-anchor">WithProperties</a> } from '@angular/elements'; import { PopupComponent } from './popup.component'; @<a href="api/core/Injectable" class="code-anchor">Injectable</a>() export class PopupService { constructor(private injector: <a href="api/core/Injector" class="code-anchor">Injector</a>, private applicationRef: <a href="api/core/ApplicationRef" class="code-anchor">ApplicationRef</a>, private componentFactoryResolver: <a href="api/core/ComponentFactoryResolver" class="code-anchor">ComponentFactoryResolver</a>) {} // Previous dynamic-loading method required you to set up infrastructure // before adding the popup to the DOM. showAsComponent(<a href="api/common/http/HttpErrorResponse#message" class="code-anchor">message</a>: string) { // Create element const popup = document.createElement('popup-component'); // Create the component and wire it up with the element const factory = this.componentFactoryResolver.resolveComponentFactory(PopupComponent); const popupComponentRef = factory.create(this.injector, [], popup); // Attach to the view so that the change detector knows to run this.applicationRef.attachView(popupComponentRef.hostView); // Listen to the close event popupComponentRef.instance.closed.subscribe(() =&gt; { document.body.removeChild(popup); this.applicationRef.detachView(popupComponentRef.hostView); }); // Set the <a href="api/common/http/HttpErrorResponse#message" class="code-anchor">message</a> popupComponentRef.instance.message = <a href="api/common/http/HttpErrorResponse#message" class="code-anchor">message</a>; // Add to the DOM document.body.appendChild(popup); } // This uses the new custom-element method to add the popup to the DOM. showAsElement(<a href="api/common/http/HttpErrorResponse#message" class="code-anchor">message</a>: string) { // Create element const popupEl: <a href="api/elements/NgElement" class="code-anchor">NgElement</a> &amp; <a href="api/elements/WithProperties" class="code-anchor">WithProperties</a>&lt;PopupComponent&gt; = document.createElement('popup-element') as any; // Listen to the close event popupEl.addEventListener('closed', () =&gt; document.body.removeChild(popupEl)); // Set the <a href="api/common/http/HttpErrorResponse#message" class="code-anchor">message</a> popupEl.message = <a href="api/common/http/HttpErrorResponse#message" class="code-anchor">message</a>; // Add to the DOM document.body.appendChild(popupEl); } }</code-pane><code-pane header="app.module.ts" path="elements/src/app/app.module.ts">import { <a href="api/core/NgModule" class="code-anchor">NgModule</a> } from '@angular/core'; import { <a href="api/platform-browser/BrowserModule" class="code-anchor">BrowserModule</a> } from '@angular/platform-browser'; import { <a href="api/platform-browser/animations/BrowserAnimationsModule" class="code-anchor">BrowserAnimationsModule</a> } from '@angular/platform-browser/animations'; import { AppComponent } from './app.component'; import { PopupComponent } from './popup.component'; import { PopupService } from './popup.service'; // Include the `PopupService` provider, // but exclude `PopupComponent` from <a href="" class="code-anchor">compilation</a>, // because it will be added dynamically. @<a href="api/core/NgModule" class="code-anchor">NgModule</a>({ imports: [<a href="api/platform-browser/BrowserModule" class="code-anchor">BrowserModule</a>, <a href="api/platform-browser/animations/BrowserAnimationsModule" class="code-anchor">BrowserAnimationsModule</a>], providers: [PopupService], declarations: [AppComponent, PopupComponent], bootstrap: [AppComponent], entryComponents: [PopupComponent], }) export class AppModule { }</code-pane><code-pane header="app.component.ts" path="elements/src/app/app.component.ts">import { <a href="api/core/Component" class="code-anchor">Component</a>, <a href="api/core/Injector" class="code-anchor">Injector</a> } from '@angular/core'; import { <a href="api/elements/createCustomElement" class="code-anchor">createCustomElement</a> } from '@angular/elements'; import { PopupService } from './popup.service'; import { PopupComponent } from './popup.component'; @<a href="api/core/Component" class="code-anchor">Component</a>({ selector: 'app-root', template: ` &lt;input #input value="Message"&gt; &lt;button (click)="popup.showAsComponent(input.value)"&gt;Show as component&lt;/button&gt; &lt;button (click)="popup.showAsElement(input.value)"&gt;Show as element&lt;/button&gt; `, }) export class AppComponent { constructor(injector: <a href="api/core/Injector" class="code-anchor">Injector</a>, public popup: PopupService) { // Convert `PopupComponent` to a custom element. const PopupElement = <a href="api/elements/createCustomElement" class="code-anchor">createCustomElement</a>(PopupComponent, {injector}); // Register the custom element with the browser. customElements.define('popup-element', PopupElement); } }</code-pane></div><mat-card class="mat-card"><mat-tab-group class="mat-tab-group code-tab-group mat-primary"><mat-tab-header class="mat-tab-header"><div aria-hidden="true" mat-ripple="" class="mat-ripple mat-tab-header-pagination mat-tab-header-pagination-before mat-elevation-z4 mat-tab-header-pagination-disabled"><div class="mat-tab-header-pagination-chevron"></div></div><div class="mat-tab-label-container"><div role="tablist" class="mat-tab-list" style="transform:translateX(0)"><div class="mat-tab-labels"><div role="tab" mattablabelwrapper="" mat-ripple="" cdkmonitorelementfocus="" class="mat-ripple mat-tab-label mat-tab-label-active ng-star-inserted" id="mat-tab-label-0-0" tabindex="0" aria-posinset="1" aria-setsize="4" aria-controls="mat-tab-content-0-0" aria-selected="true" aria-disabled="false"><div class="mat-tab-label-content"><span class="ng-star-inserted">popup.component.ts</span></div></div><div role="tab" mattablabelwrapper="" mat-ripple="" cdkmonitorelementfocus="" class="mat-ripple mat-tab-label ng-star-inserted" id="mat-tab-label-0-1" tabindex="-1" aria-posinset="2" aria-setsize="4" aria-controls="mat-tab-content-0-1" aria-selected="false" aria-disabled="false"><div class="mat-tab-label-content"><span class="ng-star-inserted">popup.service.ts</span></div></div><div role="tab" mattablabelwrapper="" mat-ripple="" cdkmonitorelementfocus="" class="mat-ripple mat-tab-label ng-star-inserted" id="mat-tab-label-0-2" tabindex="-1" aria-posinset="3" aria-setsize="4" aria-controls="mat-tab-content-0-2" aria-selected="false" aria-disabled="false"><div class="mat-tab-label-content"><span class="ng-star-inserted">app.module.ts</span></div></div><div role="tab" mattablabelwrapper="" mat-ripple="" cdkmonitorelementfocus="" class="mat-ripple mat-tab-label ng-star-inserted" id="mat-tab-label-0-3" tabindex="-1" aria-posinset="4" aria-setsize="4" aria-controls="mat-tab-content-0-3" aria-selected="false" aria-disabled="false"><div class="mat-tab-label-content"><span class="ng-star-inserted">app.component.ts</span></div></div></div><mat-ink-bar class="mat-ink-bar" style="visibility:visible;left:0;width:175px"></mat-ink-bar></div></div><div aria-hidden="true" mat-ripple="" class="mat-ripple mat-tab-header-pagination mat-tab-header-pagination-after mat-elevation-z4 mat-tab-header-pagination-disabled"><div class="mat-tab-header-pagination-chevron"></div></div></mat-tab-header><div class="mat-tab-body-wrapper"><mat-tab-body role="tabpanel" class="mat-tab-body ng-tns-c50-2 mat-tab-body-active ng-star-inserted" id="mat-tab-content-0-0" aria-labelledby="mat-tab-label-0-0"><div class="mat-tab-body-content ng-tns-c50-2 ng-trigger ng-trigger-translateTab" style="transform:none"><aio-code class="ng-star-inserted" style=""><pre class="lang- prettyprint">      <button title="Copy code snippet" class="material-icons copy-button no-print ng-star-inserted" aria-label="Copy code snippet from popup.component.ts">
        <span aria-hidden="true">content_copy</span>
      </button>
      <code class="animated fadeIn"><span class="kwd">import</span><span class="pln"> </span><span class="pun">{</span><span class="pln"> </span><a href="api/core/Component" class="code-anchor"><span class="typ">Component</span></a><span class="pun">,</span><span class="pln"> </span><a href="api/core/EventEmitter" class="code-anchor"><span class="typ">EventEmitter</span></a><span class="pun">,</span><span class="pln"> </span><a href="api/core/Input" class="code-anchor"><span class="typ">Input</span></a><span class="pun">,</span><span class="pln"> </span><a href="api/core/Output" class="code-anchor"><span class="typ">Output</span></a><span class="pln"> </span><span class="pun">}</span><span class="pln"> </span><span class="kwd">from</span><span class="pln"> </span><span class="str">'@angular/core'</span><span class="pun">;</span><span class="pln">
</span><span class="kwd">import</span><span class="pln"> </span><span class="pun">{</span><span class="pln"> </span><a href="api/animations/animate" class="code-anchor"><span class="pln">animate</span></a><span class="pun">,</span><span class="pln"> </span><a href="api/animations/state" class="code-anchor"><span class="pln">state</span></a><span class="pun">,</span><span class="pln"> </span><a href="api/animations/style" class="code-anchor"><span class="pln">style</span></a><span class="pun">,</span><span class="pln"> </span><a href="api/animations/transition" class="code-anchor"><span class="pln">transition</span></a><span class="pun">,</span><span class="pln"> </span><a href="api/animations/trigger" class="code-anchor"><span class="pln">trigger</span></a><span class="pln"> </span><span class="pun">}</span><span class="pln"> </span><span class="kwd">from</span><span class="pln"> </span><span class="str">'@angular/animations'</span><span class="pun">;</span><span class="pln">

</span><span class="lit">@</span><a href="api/core/Component" class="code-anchor"><span class="lit">Component</span></a><span class="pun">({</span><span class="pln">
  selector</span><span class="pun">:</span><span class="pln"> </span><span class="str">'my-popup'</span><span class="pun">,</span><span class="pln">
  </span><span class="kwd">template</span><span class="pun">:</span><span class="pln"> </span><span class="str">`
    &lt;span&gt;Popup: {{</span><a href="api/common/http/HttpErrorResponse#message" class="code-anchor"><span class="str">message</span></a><span class="str">}}&lt;/span&gt;
    &lt;button (click)="closed.next()"&gt;&amp;#x2716;&lt;/button&gt;
  `</span><span class="pun">,</span><span class="pln">
  </span><a href="api/core/Directive#host" class="code-anchor"><span class="pln">host</span></a><span class="pun">:</span><span class="pln"> </span><span class="pun">{</span><span class="pln">
    </span><span class="str">'[@</span><a href="api/animations/state" class="code-anchor"><span class="str">state</span></a><span class="str">]'</span><span class="pun">:</span><span class="pln"> </span><span class="str">'</span><a href="api/animations/state" class="code-anchor"><span class="str">state</span></a><span class="str">'</span><span class="pun">,</span><span class="pln">
  </span><span class="pun">},</span><span class="pln">
  animations</span><span class="pun">:</span><span class="pln"> </span><span class="pun">[</span><span class="pln">
    </span><a href="api/animations/trigger" class="code-anchor"><span class="pln">trigger</span></a><span class="pun">(</span><span class="str">'</span><a href="api/animations/state" class="code-anchor"><span class="str">state</span></a><span class="str">'</span><span class="pun">,</span><span class="pln"> </span><span class="pun">[</span><span class="pln">
      </span><a href="api/animations/state" class="code-anchor"><span class="pln">state</span></a><span class="pun">(</span><span class="str">'opened'</span><span class="pun">,</span><span class="pln"> </span><a href="api/animations/style" class="code-anchor"><span class="pln">style</span></a><span class="pun">({</span><span class="pln">transform</span><span class="pun">:</span><span class="pln"> </span><span class="str">'translateY(0%)'</span><span class="pun">})),</span><span class="pln">
      </span><a href="api/animations/state" class="code-anchor"><span class="pln">state</span></a><span class="pun">(</span><span class="str">'void, closed'</span><span class="pun">,</span><span class="pln"> </span><a href="api/animations/style" class="code-anchor"><span class="pln">style</span></a><span class="pun">({</span><span class="pln">transform</span><span class="pun">:</span><span class="pln"> </span><span class="str">'translateY(100%)'</span><span class="pun">,</span><span class="pln"> opacity</span><span class="pun">:</span><span class="pln"> </span><span class="lit">0</span><span class="pun">})),</span><span class="pln">
      </span><a href="api/animations/transition" class="code-anchor"><span class="pln">transition</span></a><span class="pun">(</span><span class="str">'* =&gt; *'</span><span class="pun">,</span><span class="pln"> </span><a href="api/animations/animate" class="code-anchor"><span class="pln">animate</span></a><span class="pun">(</span><span class="str">'100ms ease-in'</span><span class="pun">)),</span><span class="pln">
    </span><span class="pun">])</span><span class="pln">
  </span><span class="pun">],</span><span class="pln">
  styles</span><span class="pun">:</span><span class="pln"> </span><span class="pun">[</span><span class="str">`
    :</span><a href="api/core/Directive#host" class="code-anchor"><span class="str">host</span></a><span class="str"> {
      </span><a href="api/router/Scroll#position" class="code-anchor"><span class="str">position</span></a><span class="str">: absolute;
      bottom: 0;
      left: 0;
      right: 0;
      background: #009cff;
      height: 48px;
      padding: 16px;
      display: flex;
      justify-content: space-between;
      align-items: center;
      border-top: 1px solid black;
      font-size: 24px;
    }

    button {
      border-radius: 50%;
    }
  `</span><span class="pun">]</span><span class="pln">
</span><span class="pun">})</span><span class="pln">
</span><span class="kwd">export</span><span class="pln"> </span><span class="kwd">class</span><span class="pln"> </span><span class="typ">PopupComponent</span><span class="pln"> </span><span class="pun">{</span><span class="pln">
  </span><span class="kwd">private</span><span class="pln"> </span><a href="api/animations/state" class="code-anchor"><span class="pln">state</span></a><span class="pun">:</span><span class="pln"> </span><span class="str">'opened'</span><span class="pln"> </span><span class="pun">|</span><span class="pln"> </span><span class="str">'closed'</span><span class="pln"> </span><span class="pun">=</span><span class="pln"> </span><span class="str">'closed'</span><span class="pun">;</span><span class="pln">

  </span><span class="lit">@</span><a href="api/core/Input" class="code-anchor"><span class="lit">Input</span></a><span class="pun">()</span><span class="pln">
  </span><span class="kwd">set</span><span class="pln"> </span><a href="api/common/http/HttpErrorResponse#message" class="code-anchor"><span class="pln">message</span></a><span class="pun">(</span><a href="api/common/http/HttpErrorResponse#message" class="code-anchor"><span class="pln">message</span></a><span class="pun">:</span><span class="pln"> </span><span class="kwd">string</span><span class="pun">)</span><span class="pln"> </span><span class="pun">{</span><span class="pln">
    </span><span class="kwd">this</span><span class="pun">.</span><span class="pln">_message </span><span class="pun">=</span><span class="pln"> </span><a href="api/common/http/HttpErrorResponse#message" class="code-anchor"><span class="pln">message</span></a><span class="pun">;</span><span class="pln">
    </span><span class="kwd">this</span><span class="pun">.</span><span class="pln">state </span><span class="pun">=</span><span class="pln"> </span><span class="str">'opened'</span><span class="pun">;</span><span class="pln">
  </span><span class="pun">}</span><span class="pln">
  </span><span class="kwd">get</span><span class="pln"> </span><a href="api/common/http/HttpErrorResponse#message" class="code-anchor"><span class="pln">message</span></a><span class="pun">():</span><span class="pln"> </span><span class="kwd">string</span><span class="pln"> </span><span class="pun">{</span><span class="pln"> </span><span class="kwd">return</span><span class="pln"> </span><span class="kwd">this</span><span class="pun">.</span><span class="pln">_message</span><span class="pun">;</span><span class="pln"> </span><span class="pun">}</span><span class="pln">
  _message</span><span class="pun">:</span><span class="pln"> </span><span class="kwd">string</span><span class="pun">;</span><span class="pln">

  </span><span class="lit">@</span><a href="api/core/Output" class="code-anchor"><span class="lit">Output</span></a><span class="pun">()</span><span class="pln">
  closed </span><span class="pun">=</span><span class="pln"> </span><span class="kwd">new</span><span class="pln"> </span><a href="api/core/EventEmitter" class="code-anchor"><span class="typ">EventEmitter</span></a><span class="pun">();</span><span class="pln">
</span><span class="pun">}</span></code>
    </pre></aio-code></div></mat-tab-body><mat-tab-body role="tabpanel" class="mat-tab-body ng-tns-c50-3 ng-star-inserted" id="mat-tab-content-0-1" aria-labelledby="mat-tab-label-0-1"><div class="mat-tab-body-content ng-tns-c50-3 ng-trigger ng-trigger-translateTab" style="transform:translate3d(100%,0,0);min-height:1px"></div></mat-tab-body><mat-tab-body role="tabpanel" class="mat-tab-body ng-tns-c50-4 ng-star-inserted" id="mat-tab-content-0-2" aria-labelledby="mat-tab-label-0-2"><div class="mat-tab-body-content ng-tns-c50-4 ng-trigger ng-trigger-translateTab" style="transform:translate3d(100%,0,0);min-height:1px"></div></mat-tab-body><mat-tab-body role="tabpanel" class="mat-tab-body ng-tns-c50-5 ng-star-inserted" id="mat-tab-content-0-3" aria-labelledby="mat-tab-label-0-3"><div class="mat-tab-body-content ng-tns-c50-5 ng-trigger ng-trigger-translateTab" style="transform:translate3d(100%,0,0);min-height:1px"></div></mat-tab-body></div></mat-tab-group></mat-card></code-tabs><p translation-result="on">你可以到<live-example downloadonly="" ng-version="9.0.0-rc.11"><span style="display:none">这里</span><span><span class="ng-star-inserted"><a download="" title="这里" href="generated/zips/elements/elements.zip">这里</a></span></span></live-example>下载本例子的完整代码。</p><p translation-origin="off">You can download the full code for the example<live-example downloadonly="" ng-version="9.0.0-rc.11"><span style="display:none">here</span><span><span class="ng-star-inserted"><a download="" title="here" href="generated/zips/elements/elements.zip">here</a></span></span></live-example>.</p><h2 id="typings-for-custom-elements" translation-result="on">为自定义元素添加类型支持<a title="Link to this heading" class="header-link" aria-hidden="true" href="guide/elements#typings-for-custom-elements"><i class="material-icons">link</i></a></h2><h2 translation-origin="off" id="typings-for-custom-elements">Typings for custom elements<a title="Link to this heading" class="header-link" aria-hidden="true" href="guide/elements#typings-for-custom-elements"><i class="material-icons">link</i></a></h2><p translation-result="on">一般的 DOM API，比如 <code>document.createElement()</code> 或 <code>document.querySelector()</code>，会返回一个与指定的参数相匹配的元素类型。比如，调用 <code>document.createElement('a')</code> 会返回 <code>HTMLAnchorElement</code>，这样 TypeScript 就会知道它有一个 <code>href</code> 属性，而 <code>document.createElement('div')</code> 会返回 <code>HTMLDivElement</code>，这样 TypeScript 就会知道它没有 <code>href</code> 属性。</p><p translation-origin="off">Generic DOM APIs, such as <code>document.createElement()</code> or <code>document.querySelector()</code>, return an element type that is appropriate for the specified arguments. For example, calling <code>document.createElement('a')</code> will return an <code>HTMLAnchorElement</code>, which TypeScript knows has an <code>href</code> property. Similarly, <code>document.createElement('div')</code> will return an <code>HTMLDivElement</code>, which TypeScript knows has no <code>href</code> property.</p><p translation-result="on">当调用未知元素（比如自定义的元素名 <code>popup-element</code>）时，该方法会返回泛化类型，比如 <code>HTMLELement</code>，这时候 TypeScript 就无法推断出所返回元素的正确类型。</p><p translation-origin="off">When called with unknown elements, such as a custom element name (<code>popup-element</code> in our example), the methods will return a generic type, such as <code>HTMLElement</code>, since TypeScript can't infer the correct type of the returned element.</p><p translation-result="on">用 Angular 创建的自定义元素会扩展 <code><a href="api/elements/NgElement" class="code-anchor">NgElement</a></code> 类型（而它扩展了 <code>HTMLElement</code>）。除此之外，这些自定义元素还拥有相应组件的每个输入属性。比如，<code>popup-element</code> 元素具有一个 <code>string</code> 型的 <code><a href="api/common/http/HttpErrorResponse#message" class="code-anchor">message</a></code> 属性。</p><p translation-origin="off">Custom elements created with Angular extend <code><a href="api/elements/NgElement" class="code-anchor">NgElement</a></code> (which in turn extends <code>HTMLElement</code>). Additionally, these custom elements will have a property for each input of the corresponding component. For example, our <code>popup-element</code> will have a <code><a href="api/common/http/HttpErrorResponse#message" class="code-anchor">message</a></code> property of type <code>string</code>.</p><p translation-result="on">如果你要让你的自定义元素获得正确的类型，还可使用一些选项。假设你要创建一个基于下列组件的自定义元素 <code>my-dialog</code>：</p><p translation-origin="off">There are a few options if you want to get correct types for your custom elements. Let's assume you create a <code>my-dialog</code> custom element based on the following component:</p><code-example language="ts" ng-version="9.0.0-rc.11"><div style="display:none">@<a href="api/core/Component" class="code-anchor">Component</a>(...) class MyDialog { @<a href="api/core/Input" class="code-anchor">Input</a>() content: string; }</div><aio-code><pre class="lang-ts prettyprint">      <button title="Copy code snippet" class="material-icons copy-button no-print ng-star-inserted" aria-label="">
        <span aria-hidden="true">content_copy</span>
      </button>
      <code class="animated fadeIn"><span class="lit">@</span><a href="api/core/Component" class="code-anchor"><span class="lit">Component</span></a><span class="pun">(...)</span><span class="pln">
</span><span class="kwd">class</span><span class="pln"> </span><span class="typ">MyDialog</span><span class="pln"> </span><span class="pun">{</span><span class="pln">
  </span><span class="lit">@</span><a href="api/core/Input" class="code-anchor"><span class="lit">Input</span></a><span class="pun">()</span><span class="pln"> content</span><span class="pun">:</span><span class="pln"> string</span><span class="pun">;</span><span class="pln">
</span><span class="pun">}</span></code>
    </pre></aio-code></code-example><p translation-result="on">获得精确类型的最简单方式是把相关 DOM 方法的返回值转换成正确的类型。要做到这一点，你可以使用 <code><a href="api/elements/NgElement" class="code-anchor">NgElement</a></code> 和 <code><a href="api/elements/WithProperties" class="code-anchor">WithProperties</a></code> 类型（都导出自 <code>@angular/elements</code>）：</p><p translation-origin="off">The most straight forward way to get accurate typings is to cast the return value of the relevant DOM methods to the correct type. For that, you can use the <code><a href="api/elements/NgElement" class="code-anchor">NgElement</a></code> and <code><a href="api/elements/WithProperties" class="code-anchor">WithProperties</a></code> types (both exported from <code>@angular/elements</code>):</p><code-example language="ts" ng-version="9.0.0-rc.11"><div style="display:none">const aDialog = document.createElement('my-dialog') as <a href="api/elements/NgElement" class="code-anchor">NgElement</a> &amp; <a href="api/elements/WithProperties" class="code-anchor">WithProperties</a>&lt;{content: string}&gt;; aDialog.content = 'Hello, world!'; aDialog.content = 123; // &lt;-- ERROR: TypeScript knows this should be a string. aDialog.body = 'News'; // &lt;-- ERROR: TypeScript knows there is no `body` property on `aDialog`.</div><aio-code><pre class="lang-ts prettyprint">      <button title="Copy code snippet" class="material-icons copy-button no-print ng-star-inserted" aria-label="">
        <span aria-hidden="true">content_copy</span>
      </button>
      <code class="animated fadeIn"><span class="kwd">const</span><span class="pln"> aDialog </span><span class="pun">=</span><span class="pln"> document</span><span class="pun">.</span><span class="pln">createElement</span><span class="pun">(</span><span class="str">'my-dialog'</span><span class="pun">)</span><span class="pln"> as </span><a href="api/elements/NgElement" class="code-anchor"><span class="typ">NgElement</span></a><span class="pln"> </span><span class="pun">&amp;</span><span class="pln"> </span><a href="api/elements/WithProperties" class="code-anchor"><span class="typ">WithProperties</span></a><span class="pun">&lt;{</span><span class="pln">content</span><span class="pun">:</span><span class="pln"> string</span><span class="pun">}&gt;;</span><span class="pln">
aDialog</span><span class="pun">.</span><span class="pln">content </span><span class="pun">=</span><span class="pln"> </span><span class="str">'Hello, world!'</span><span class="pun">;</span><span class="pln">
aDialog</span><span class="pun">.</span><span class="pln">content </span><span class="pun">=</span><span class="pln"> </span><span class="lit">123</span><span class="pun">;</span><span class="pln">  </span><span class="com">// &lt;-- ERROR: TypeScript knows this should be a string.</span><span class="pln">
aDialog</span><span class="pun">.</span><span class="pln">body </span><span class="pun">=</span><span class="pln"> </span><span class="str">'News'</span><span class="pun">;</span><span class="pln">  </span><span class="com">// &lt;-- ERROR: TypeScript knows there is no `body` property on `aDialog`.</span></code>
    </pre></aio-code></code-example><p translation-result="on">这是一种让你的自定义元素快速获得 TypeScript 特性（比如类型检查和自动完成支持）的好办法，不过如果你要在多个地方使用它，可能会有点啰嗦，因为不得不在每个地方对返回类型做转换。</p><p translation-origin="off">This is a good way to quickly get TypeScript features, such as type checking and autocomplete support, for you custom element. But it can get cumbersome if you need it in several places, because you have to cast the return type on every occurrence.</p><p translation-result="on">另一种方式可以对每个自定义元素的类型只声明一次。你可以扩展 <code>HTMLElementTagNameMap</code>，TypeScript 会在 DOM 方法（如 <code>document.createElement()</code>、<code>document.querySelector()</code> 等）中用它来根据标签名推断返回元素的类型。</p><p translation-origin="off">An alternative way, that only requires defining each custom element's type once, is augmenting the <code>HTMLElementTagNameMap</code>, which TypeScript uses to infer the type of a returned element based on its tag name (for DOM methods such as <code>document.createElement()</code>, <code>document.querySelector()</code>, etc.):</p><code-example language="ts" ng-version="9.0.0-rc.11"><div style="display:none">declare <a href="api/core/global" class="code-anchor">global</a> { interface HTMLElementTagNameMap { 'my-dialog': <a href="api/elements/NgElement" class="code-anchor">NgElement</a> &amp; <a href="api/elements/WithProperties" class="code-anchor">WithProperties</a>&lt;{content: string}&gt;; 'my-other-element': <a href="api/elements/NgElement" class="code-anchor">NgElement</a> &amp; <a href="api/elements/WithProperties" class="code-anchor">WithProperties</a>&lt;{foo: 'bar'}&gt;; ... } }</div><aio-code><pre class="lang-ts prettyprint">      <button title="Copy code snippet" class="material-icons copy-button no-print ng-star-inserted" aria-label="">
        <span aria-hidden="true">content_copy</span>
      </button>
      <code class="animated fadeIn"><span class="pln">declare </span><a href="api/core/global" class="code-anchor"><span class="pln">global</span></a><span class="pln"> </span><span class="pun">{</span><span class="pln">
  </span><span class="kwd">interface</span><span class="pln"> </span><span class="typ">HTMLElementTagNameMap</span><span class="pln"> </span><span class="pun">{</span><span class="pln">
    </span><span class="str">'my-dialog'</span><span class="pun">:</span><span class="pln"> </span><a href="api/elements/NgElement" class="code-anchor"><span class="typ">NgElement</span></a><span class="pln"> </span><span class="pun">&amp;</span><span class="pln"> </span><a href="api/elements/WithProperties" class="code-anchor"><span class="typ">WithProperties</span></a><span class="pun">&lt;{</span><span class="pln">content</span><span class="pun">:</span><span class="pln"> string</span><span class="pun">}&gt;;</span><span class="pln">
    </span><span class="str">'my-other-element'</span><span class="pun">:</span><span class="pln"> </span><a href="api/elements/NgElement" class="code-anchor"><span class="typ">NgElement</span></a><span class="pln"> </span><span class="pun">&amp;</span><span class="pln"> </span><a href="api/elements/WithProperties" class="code-anchor"><span class="typ">WithProperties</span></a><span class="pun">&lt;{</span><span class="pln">foo</span><span class="pun">:</span><span class="pln"> </span><span class="str">'bar'</span><span class="pun">}&gt;;</span><span class="pln">
    </span><span class="pun">...</span><span class="pln">
  </span><span class="pun">}</span><span class="pln">
</span><span class="pun">}</span></code>
    </pre></aio-code></code-example><p translation-result="on">现在，TypeScript 就可以像内置元素一样推断出它的正确类型了：</p><p translation-origin="off">Now, TypeScript can infer the correct type the same way it does for built-in elements:</p><code-example language="ts" ng-version="9.0.0-rc.11"><div style="display:none">document.createElement('div') //--&gt; HTMLDivElement (built-in element) document.querySelector('foo') //--&gt; Element (unknown element) document.createElement('my-dialog') //--&gt; <a href="api/elements/NgElement" class="code-anchor">NgElement</a> &amp; <a href="api/elements/WithProperties" class="code-anchor">WithProperties</a>&lt;{content: string}&gt; (custom element) document.querySelector('my-other-element') //--&gt; <a href="api/elements/NgElement" class="code-anchor">NgElement</a> &amp; <a href="api/elements/WithProperties" class="code-anchor">WithProperties</a>&lt;{foo: 'bar'}&gt; (custom element)</div><aio-code><pre class="lang-ts prettyprint">      <button title="Copy code snippet" class="material-icons copy-button no-print ng-star-inserted" aria-label="">
        <span aria-hidden="true">content_copy</span>
      </button>
      <code class="animated fadeIn"><span class="pln">document</span><span class="pun">.</span><span class="pln">createElement</span><span class="pun">(</span><span class="str">'div'</span><span class="pun">)</span><span class="pln">               </span><span class="com">//--&gt; HTMLDivElement (built-in element)</span><span class="pln">
document</span><span class="pun">.</span><span class="pln">querySelector</span><span class="pun">(</span><span class="str">'foo'</span><span class="pun">)</span><span class="pln">               </span><span class="com">//--&gt; Element        (unknown element)</span><span class="pln">
document</span><span class="pun">.</span><span class="pln">createElement</span><span class="pun">(</span><span class="str">'my-dialog'</span><span class="pun">)</span><span class="pln">         </span><span class="com">//--&gt; </span><a href="api/elements/NgElement" class="code-anchor"><span class="com">NgElement</span></a><span class="com"> &amp; </span><a href="api/elements/WithProperties" class="code-anchor"><span class="com">WithProperties</span></a><span class="com">&lt;{content: string}&gt; (custom element)</span><span class="pln">
document</span><span class="pun">.</span><span class="pln">querySelector</span><span class="pun">(</span><span class="str">'my-other-element'</span><span class="pun">)</span><span class="pln">  </span><span class="com">//--&gt; </span><a href="api/elements/NgElement" class="code-anchor"><span class="com">NgElement</span></a><span class="com"> &amp; </span><a href="api/elements/WithProperties" class="code-anchor"><span class="com">WithProperties</span></a><span class="com">&lt;{foo: 'bar'}&gt;      (custom element)</span></code>
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